Method of and apparatus for cutting up semi-plastic light weight concrete bodies

ABSTRACT

Cutting up of a semi-plastic cellular light weight concrete body by passing string-like cutting members having, when operative, a substantially vertical extension in a horizontal direction therethrough is effected while the body to be cut is kept freely suspended from a perforated bottom of a hood-like suspension device, in which a sufficient vacuum is created to maintain adhesion by suction between the top of the body and said perforated bottom. The cutting members pass through and are moved along in slots formed in the bottom of the suspension device, their upper ends being actuated for movement above said bottom and their lower ends being separately actuated by driving means mounted in a stand separate from the suspension device but engaging therewith in a guiding manner, when cutting is effected.

United States Patent Giiransson Apr. 17, 1973 METHOD OF AND APPARATUS FOR CUTTING UP SEMI-PLASTIC LIGHT WEIGHT CONCRETE BODIES Att0meyFred C. Philpitt [75] Inventor: Rolf Erik Giiransson, Alvsjo,

Sweden 57 ABSTRACT [73] Assignee: Internationella Siporex Aktiebolaget, Cutting up of a senmplastic cellular light weight Stockholm Sweden concrete body by passing string-like cutting members 22 Fil July 6 1970 having, when operative, a substantially vertical extension in a horizontal direction therethrough is effected [211 App! 52372 while the body to be cut is kept freely suspended from a perforated bottom of a hood-like suspension device, 30 Foreign A li ti priority m in which a suificient vacuum is created to maintain adhesion by suction between the top of the body and July 10, 1969 Sweden ..9790/69 Said perforated bottom. The cutting members pass through and are moved along in slots formed in the [52] U.S.Cl. ..83/56, 83/374, 83/451, bottom of the Suspension device their upper ends 83/614 83/618 being actuated for movement above said bottom and [51] Int. Cl. ..B26d 7/00 their lower ends being Separately actuated by driving Fleld OI ..83/45I, means mounted in a tand eparate from the Suspen 14, 22, 56 sion device but engaging therewith in a guiding manner, when cutting is effected. [56] References Cited 7 7 Claims, 3 Drawing Figures UNITED STATES PATENTS 1,997,843 4/1935 Warrell ..83/22 X Z 4 f2 9 {31 1 L l 1 f 1 i I I,

PATENTEBAPR 1 71973 METHOD OF AND APPARATUS FOR CUTTING UP SEMI-PLASTIC LIGHT WEIGHT CONCRETE BODIES This invention relates to cutting of semi-plastic bodies and, more particularly, to the cutting up of solidified but yet unhardened cellular light weight concrete bodies by passing in a horizontal direction string-like cutting members having a substantially vertical extension through said bodies.

Heretofore it was common practice in cutting up a semi-plastic cellular concrete body to rest the body on some sort of bed, called a cutting bed, which could in certain cases be stationary and in other cases movable and then take the form of a'truck or carriage. The cutting members were commonly mounted and vertically stretched in special frameor fork-like holder means which, when the cutting bed was stationary, had to be movable and, when the cutting bed was movable, could be either stationary or movable, as desired. In certain cutting beds there were provided longitudinally extending slots, through which the cutting members could pass, so that the lower member of each cutting frame or fork could find an unobstructed passage beneath the body supporting surface of the cutting bed. In certain other equipments the body supporting surface of the cutting bed was divided into transverse sections which could be lowered in succession from the bottom of the body to be cut in order to provide a free passage for the lower cutting frame member and then again returned to a body supporting position.

However, the use of these known cutting beds on which the bodies are rested when being cut involves certain drawbacks, one of which is that the bottom of the cellular concrete body, which is usually large and heavy and the material of which is very fragil, frequently becomes damaged either in connection with the lifting away of the body from the cutting bed or already during the cutting process in those cases, when the cutting bed comprises the movable sections referred to above. The damages here in question occur because of the tendency of the semi-plastic concrete material to stick to the supporting surface so that pieces of the body are broken away, when separation is to be effected. In addition, it has been found in practice that it is very difficult to obtain a complete plane congruity between the bottom of the body and the supporting surface of the cutting bed, and the lack of such congruity frequently results in objectionable cracks in the large and heavy body. Furthermore the use of conventional cutting beds makes it almost impossible or at least very complicated to subject the bottom of the cellular concrete body to some sort of shaping, planing or grooving, which is frequently desirable. ln most cases such working of the bottom of the body cannot at all be performed before the body is placed on the cutting bed cutting up of the body while the same is kept freely suspended from a perforated bottom of a hood-like suspension device, in which a sufficient vacuum is created to maintain adhesion by suction between the top of the body and the perforated bottom of the suspension device, the upper ends of the cutting members being passed through slots in said bottom and being actuated for movement in the cutting direction above said bottom.

It is well known within the art of manufacturing cellular concrete products to transport semi-plastic bodies, viz. solidified but yet unhardened cellular light weight concrete bodies, between different supports or beds by means of so-called suction heads, which are lowered into contact with the top of the body and then evacuated in a manner to cause the body to adhere by suction to the head, so that the whole can be lifted away as a unit, but heretofore no cutting operations have been performed with the bodies suspended in such heads. Instead the bodies havealways been deposited on some sort of cutting bed before being cut up into pieces.

Among the advantages offered by this invention the following has been found particularly valuable: The cutting up of the body can take place subsequent to any desired working of the entirely free bottom of the suspended body. Immediately after cutting the body can be deposited on that same support, on which it is to be subsequently steamhardened in the autoclave. This, of course, entirely eliminates the need for some sort of cutting bed or intermediate body support in the manufacturing plant. The risks of damaging the body are highly reduced if at all existing, because the contact pressure between the top of the body and the perforated bottom of the suspension device is very small compared with the contact pressure obtained between a similar body and a cutting bed supporting the entire load of the body. Accordingly the body material will show practically no tendency to stick or bind to that perforated bottom. It is also much easier to prepare the top of the cellular concrete body for a perfect and harmless engagement with the suspension device than to adapt the bottom of the body to an ordinary cutting bed, because the top of the body can easily be, and most frequently is, subjected to planing already when the body is still lying on the mold bottom or the casting bed, on which it was previously cast and expanded to become cellular.

Although the invention is basically concerned with the proceeding above referred to in conjunction with the cutting up of a semi-plastic cellular light weight concrete body, it also includes an apparatus for carrying out said proceeding or method. The objects of this part of the invention are, of course, mainly to provide suitable means to achieve the advantages referred to above.

For further elucidation of the invention reference will now be had to the accompanying drawing illustrating in a somewhat simplified and diagrammatic manner a preferred form of an apparatus for cutting up semiplastic cellular light weight concrete bodies. In the drawing:

FIG. 1 shows a longitudinal sectional elevation of the apparatus, a semi-plastic body being suspended therein and partly cut through in its longitudinal direction,

FIG. 2 is a transverse sectional elevation through the apparatus shown in FIG. 1, and

FIG. 3 is a fragmentary transverse sectional elevation at an enlarged scale showing in particular the design of the bottom of the suspension device forming part of the apparatus.

In the drawing, L designates a semi-plastic cellular body, viz. a solidified but yet unhardened cellular light weight concrete body, the top of which is attached by suction to the bottom side of a suspension device, generally indicated by 2, which in its turn by means of ropes 3 or in any other suitable way is suspended from a travelling trolley or the like, not shown. The suspension device 2 is vertically movable and may also be horizontally moved between different stations in the manufacturing plant.

The suspension device 2 comprises a hood 4, the interior of which communicates with an evacuating equipment comprising a suction blower 5 mounted on top of the hood 4. By means of the blower 5 there can be created in the interior of the suspension device a sufficiently high vacuum to keep the body L lifted during the handling and cutting thereof. The hood 4 has a perforated bottom 6 comprising a number of parallel beams or channel members having perforated webs, these beams being arranged in a manner to provide longitudinally extending slots 7 between them. The slots 7 permit the passage and movement of string-like cutting members 8 having all a substantially vertical extension and being all moved in a horizontal direction coinciding with that of their respective slots, when cutting of the body L is effected.

The end portions of the beams 6 located outside the respective ends of the body L have no perforations, so that excessive sucking in of air into the hood can be avoided. For the same reason, lip-like sealing means 9 of rubber or the like are provided in the slots 7 in a manner to permit the passage of the cutting members 8 but to substantially seal the slots on either side thereof. In this manner the capacity of the suction blower 5 can be most effectively utilized.

The upper ends of the various cutting members 8 are all connected suitably through intermediary tensioning springs 10, to a common transverse attachment beam 11, the respective ends of which are connected to slides 12 being movable back and forth in synchronism along and by means of screws 13, which through suitable bevel gears and other transmissions may be driven by a motor 14. The screws 13, acting also as guides for the slides 12, extend in a direction parallel to the slots 7 in the perforated bottom 6 of the suspension device 2. As has been indicated by dash-and-dot lines in FIG. 1, the slides 12 may continue their movement in either direction a short distance beyond the ends of the body L in order to assure a complete cutting through of the body.

When the body L is to be cut, it is normally resting on a casting support or a mold bottom, not shown, and the top of the semi-plastic body has just been planed in order to remove such excess of material therefrom which can hardly be avoided, when the light weight concrete mass is caused to expand in the casting mold. The suspension device 2 is moved to a position straight above the body and lowered into contact with the top thereof. Of course, the slides 12 are then in either one of their two end positions and the cutting members 8 are kept away in any suitable manner in order not to interfere. When contact between the top of the body L and the perforated bottom 6 of the suspension device 2 is established, the suction blower 5 is started to create the necessary vacuum in the hood 4, so that the body L will be carried along when the suspension device 2 is again lifted and moved away from the casting bed to the apparatus or cutting station illustrated in the drawsuspended therefrom may first be moved to an intermediate station where appropriate working of the bottom of the body can take place, before the body is forwarded to the cutting station proper. However, such working of the body bottom, which commonly includes planing and groove-cutting, may also take place at the cutting station proper and then preferably before the cutting up of the suspended body is effected.

At the cutting station there is provided a stand or frame structure which is separate from the suspension device 2 but adapted to co-operate with the latter in a guiding manner in order to closely define their relative horizontal positions, when the cutting is effected. The stand comprises, in the example shown, four substantially vertical posts 16 between which the suspension device 2 can be lowered from above, and two horizontal guide beams 17 supported by each one pair of posts. Along each such beam 17 a slide 18 is movable under the actuation of a screw 19, the two screws 19 being synchronously driven by a motor 20 through bevel gears and suitable transmissions.

The two slides 18 are adapted to receive between them a cross beam member 15 serving as a holder for the lower ends of the cutting members 8. The cutting members 8 may either be permanently attached to the cross beam 15 and the latter releasably connected to the slides 18, or the beam 15 may be permanently secured to the slides and the cutting members 8 be releasably attached, one by one, to the beam just before the cutting operation is started. The motor 20 should, of course, be arranged to drive the slides 18 and the beam 15 substantially in synchronism with the slides 12 and the beam 11 in the suspension device 2.

With the assistance of the described arrangements included in the stationary stand, the lower ends of the cutting members 8 can thus be moved along paths parallel with those of the upper ends of the cutting members and this, of course, is due to the fact that the suspension device 2 takes up a predetermined position in relation to the stand or, more particularly, to the posts 16 forming part thereof. An accurate guidance of the suspension device 2 between the posts 16 is, in the example shown, obtained by the provision of special guide blocks 2' on the lateral sides of the suspension device, but other means may be resorted to in order to permit necessary adjustments.

As can be seen from FIGS. 1 and 2, the bottom side of the semi-plastic cellular concrete body L suspended from the suspension device 2 is completely exposed during the entire cutting operation and also before that. Consequently, the bottom of the body may easily be worked and will not be subjected to damages during the cutting up of the body. When cutting is effected, the lower ends of the cutting members 8 are disconnected If desired, the suspension device with the body L from the beam or the latter disconnected from the slides 18, as the case may be, so that the suspension device 2 can again to moved in order to deposit the cut body on its steamhardening support, the suction blower 5 being then stopped so that the body is released.

I claim:

1. The method of cutting up a semi-plastic cellular light weight concrete body which comprises: attaching the body by suction to a perforated bottom of a hollow suspension device while the body is still rested on a first support, separating the body from said first support while maintaining a sufficient vacuum in said suspension device to keep the body freely suspended therefrom, passing string-like cutting members having a substantially vertical extension in a horizontal direction through the suspended body while advancing the upper ends of said cutting members above said perforated bottom of the suspension device and the lower ends thereof below the free bottom surface of the body, and finally depositing the body on a second support when cutting is accomplished.

2. An apparatus for cutting up a semi-plastic cellular light weight concrete body by passing string-like cutting members having, when operative, a substantially vertical extension, in a horizontal direction therethrough and comprising, in combination an at least vertically movable, hollow suspension device having a perforated bottom for contacting the top of the body to be cut, evacuating means for creating a vacuum in said hollow suspension device that is sufficiently strong to effect adhesion of the body to said perforated bottom of the suspension device by suction and to thus permit lifting of the body by means of said suspension device, a plurality of cutting members having their upper ends located above said perforated bottom of the suspension device, parallel slots formed in said perforated bottom for permitting the cutting members to pass therethrough and to be moved in at least one direction along said bottom, first movable holding means for the upper ends of the cutting members, said first movable holding means being arranged above said perforated and slotted bottom of the suspension device, means incorporated in said suspension device to effect movement of said first holding means in directions parallel with said slots formed in the perforated bottom, second movable holding means for the lower ends of the cutting members, and means to effect movement of said second holding means in substantial synchronism with and along paths that are parallel with those of said first holding means, said latter means being separately provided below the suspension device, when cutting is to be effected.

3. An apparatus according to claim 2, wherein said evacuating means comprises a blower mounted on the suspension device.

4. An apparatus according to claim 2, wherein said first movable holding means for the upper ends of the cutting members comprises a transverse attachment beam extending between slides movable back and forth along guiding means arranged in the suspension device and extending parallel with the slots formed in the perforated bottom thereof.

5. An apparatus according to claim 2, wherein said suspension device is adapted to engage with and be guided by a separate stand formin a mounting for said means for moving the second ho ding means for the lower ends ofthe cutting members.

6. An apparatus according to claim 2, wherein said second movable holding means for the lower ends of the cutting members comprise a transverse attachment member common to all cutting members and releasably connectable to said means for effecting. movement thereof, when cutting is to be effected.

1 7. An apparatus according to claim 2, wherein yieldable sealing means are provided in said slots of the perforated bottom of the suspension device. 

1. The method of cutting up a semi-plastic cellular light weight concrete body which comprises: attaching the body by suction to a perforated bottom of a hollow suspension device while the body is still rested on a first support, separating the body from said first support while maintaining a sufficient vacuum in said suspension device to keep the body freely suspended therefrom, passing string-like cutting members having a substantially vertical extension in a horizontal direction through the suspended body while advancing the upper ends of said cutting members above said perforated bottom of the suspension device and the lower ends thereof below the free bottom surface of the body, and finally depositing the body on a second support when cutting is accomplished.
 2. An apparatus for cutting up a semi-plastic cellular light weight concrete body by passing string-like cutting members having, when operative, a substantially vertical extension, in a horizontal direction therethrough and comprising, in combination an at least vertically movable, hollow suspension device havinG a perforated bottom for contacting the top of the body to be cut, evacuating means for creating a vacuum in said hollow suspension device that is sufficiently strong to effect adhesion of the body to said perforated bottom of the suspension device by suction and to thus permit lifting of the body by means of said suspension device, a plurality of cutting members having their upper ends located above said perforated bottom of the suspension device, parallel slots formed in said perforated bottom for permitting the cutting members to pass therethrough and to be moved in at least one direction along said bottom, first movable holding means for the upper ends of the cutting members, said first movable holding means being arranged above said perforated and slotted bottom of the suspension device, means incorporated in said suspension device to effect movement of said first holding means in directions parallel with said slots formed in the perforated bottom, second movable holding means for the lower ends of the cutting members, and means to effect movement of said second holding means in substantial synchronism with and along paths that are parallel with those of said first holding means, said latter means being separately provided below the suspension device, when cutting is to be effected.
 3. An apparatus according to claim 2, wherein said evacuating means comprises a blower mounted on the suspension device.
 4. An apparatus according to claim 2, wherein said first movable holding means for the upper ends of the cutting members comprises a transverse attachment beam extending between slides movable back and forth along guiding means arranged in the suspension device and extending parallel with the slots formed in the perforated bottom thereof.
 5. An apparatus according to claim 2, wherein said suspension device is adapted to engage with and be guided by a separate stand forming a mounting for said means for moving the second holding means for the lower ends of the cutting members.
 6. An apparatus according to claim 2, wherein said second movable holding means for the lower ends of the cutting members comprise a transverse attachment member common to all cutting members and releasably connectable to said means for effecting movement thereof, when cutting is to be effected.
 7. An apparatus according to claim 2, wherein yieldable sealing means are provided in said slots of the perforated bottom of the suspension device. 